1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
|
// Copyright (c) 2022 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include <bench/bench.h>
#include <key.h>
#include <pubkey.h>
#include <random.h>
#include <span.h>
#include <array>
#include <cstddef>
static void BIP324_ECDH(benchmark::Bench& bench)
{
ECC_Start();
FastRandomContext rng;
std::array<std::byte, 32> key_data;
std::array<std::byte, EllSwiftPubKey::size()> our_ellswift_data;
std::array<std::byte, EllSwiftPubKey::size()> their_ellswift_data;
rng.fillrand(key_data);
rng.fillrand(our_ellswift_data);
rng.fillrand(their_ellswift_data);
bench.batch(1).unit("ecdh").run([&] {
CKey key;
key.Set(key_data.data(), key_data.data() + 32, true);
EllSwiftPubKey our_ellswift(our_ellswift_data);
EllSwiftPubKey their_ellswift(their_ellswift_data);
auto ret = key.ComputeBIP324ECDHSecret(their_ellswift, our_ellswift, true);
// To make sure that the computation is not the same on every iteration (ellswift decoding
// is variable-time), distribute bytes from the shared secret over the 3 inputs. The most
// important one is their_ellswift, because that one is actually decoded, so it's given most
// bytes. The data is copied into the middle, so that both halves are affected:
// - Copy 8 bytes from the resulting shared secret into middle of the private key.
std::copy(ret.begin(), ret.begin() + 8, key_data.begin() + 12);
// - Copy 8 bytes from the resulting shared secret into the middle of our ellswift key.
std::copy(ret.begin() + 8, ret.begin() + 16, our_ellswift_data.begin() + 28);
// - Copy 16 bytes from the resulting shared secret into the middle of their ellswift key.
std::copy(ret.begin() + 16, ret.end(), their_ellswift_data.begin() + 24);
});
ECC_Stop();
}
BENCHMARK(BIP324_ECDH, benchmark::PriorityLevel::HIGH);
|